Fluid document transporter



April 8, 1969 R. s. GLUsKlN 3,437,335

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April s, 1969 R. s. GLUsKlN FLUID DOCUMENT TRANSPORTER' Sheet Filed June 16, 1967 SMI @mom @2:25432 United States Patent O 3,437,335 FLUID DOCUMENT TRANSPORTER Richard S. Gluskin, Bala Cynwyd, Pa., assignor to Sperry Rand Corporation, New York, N.Y., a corporation of Delaware Filed June 16, 1967, Ser. No. 646,556 Int. Cl. B65l1 29/24 U.S. ICl. 271-8 11 Claims ABSTRACT OF THE DISCLOSURE A Huid motion control for document transporting is disclosed. A series of accelerating uid jets are positioned along the length of the feed bed and are angled relative to the bed so as to apply a force to the document tending to propel it down the length of the bed. A series of retarding jets are positioned along the length of the feed bed and are angled in opposition to the accelerating jets so as to apply a force to the document tending to propel the document up the bed. The uid pressure applied to the jets is modulated or sequenced so that the net force applied to the document by the accelerating jets exceeds that applied by the retarding jets whereby the document is caused to move down the bed at a rate controlled by the modulation or sequencing frequency of the applied jets.

This invention relates to a document and/or card transport device of the type found in data processing equipment, and in more particular to a transport system which utilizes fluid jets for propelling documents along a feed bed.

Background of the invention Document feeders of the type which utilize feed rolls, belts etc. to mechanically drive a document along a feed bed are well known to the art. Such systems suffer from numerous disadvantages normally attendant any mechanical paper handling system. For example, the gears, pulleys, belts, feed rolls and other moving parts are subject to wear and therefore must be periodically replaced or adjusted. Also, the mechanical gripping action of the drive mechanism on the document wears or frequently mutilates the document itself.

To avoid these problems fluid transport mechanisms have been proposed and are part of the known prior art. In these systems documents are aerodynamically transported from one station to another through the use of air jets which are trained on the document so as to provide a propelling force thereon. One such system is shown in U.S. Patent 3,136,539.

A notable disadvantage of the prior art uid transport systems, however, is that there is normally no positive control over the velocity of the document; that is, the document travels at a rate which is a function of the velocity of the uid jets. Velocity control is, of course, important when the document is used in a data processing system where the document is to be passed over a read station, for example.

Another disadvantage of the prior art uid transport systems is that they do suffer from some lack of efficiency. Specifically, it is normal in the prior art systems that all the propelling jets be on continuously. However, since it is only those jets which are trained on the document that are doing any useful work in propelling the document, those jets which are ahead or behind the document are consuming energy Without effectively imparting motion to the document.

Brief summary In accordance with the present invention a novel document transport system is provided which is free of ice the above-mentioned defects. In more particular, a document feed bed is provided which has associated therewith both accelerating and retarding jets. The accelerating jets are positioned along the length of the bed and are trained relative to the bed so as to apply a force to the document which tends to propel the document down the bed. The retarding jets are positioned along the length of the bed and are trained relative to the bed so as to apply a force to the document tending to propel the document up the bed. A fluid distributor or modulator is connected to both the accelerating and retarding jets and is arranged to modulate or sequence the action of the jets so that a net force is applied to the documents by the accelerating jets to thereby cause the document to move down the bed at a rate controlled by the modulation or sequence frequency of the distributor.

By means of the present invention, the use of mechanical drive mechanisms found in the prior art is avoided as is the adjustment and replacement problems associated therewith. The present invention also permits the transporting of documents without mechanically contacting either face of the document, thereby increasing document life. The present invention also provides for velocity control of the document motion as a function of the jet sequencing rate. Finally, the present invention, at least in one embodiment, uses only those jets which are in registration with the document to propel the document whereby the efficiency of the transport system is improved over the prior art systems.

Other objects and advantages of the present invention will become apparent upon a careful reading of the following disclosure when taken in conjunction with the accompanying drawings, in which;

FIGURE l is a simplified diagrammatic view showing one possible application of the present invention;

FIGURE 2 is a side elevational view showing a portion of applicants novel feed bed;

FIGURE 3 is an end sectional view of the feed bed taken along the lines 3--3 of FIGURE 2;

FIGURE 4 is a sectional view of the feed bed taken along the lines 4-4 of FIGURE 3;

FIGURE 5 is a sectional view of the feed bed taken along the lines 5-5 of FIGURE 3;

FIGURE 6 shows in outline form how a document is propelled by the accelerating and retarding jets;

FIGURE 7 is a schematic diagram of one typical way of sequentially energizing the accelerating jets of this invention;

FIGURE 8 is a schematic diagram of an alternate arrangement for energizing the jets in applicants invention; and

FIGURE 8a is a schematic diagram of one typical fluid wave generator 70 in FIGURE 8.

Referring now to FIGURE l there is included a supply bin 20 for holding the documents 21 to be processed; applicants novel document feed bed 24 for propelling the documents past a read station 22, for example, and a stacker 23 which receives the processed documents. In practice, a picker mechanism which is not shown, removes the documents 21 one at a time from the supply bin 20 and inserts them into the throat of the feed bed 24 where thereafter the feed bed 24 as controlled by the fluid sequencer 25 propels the cards as viewed in FIG. l from left to right past the read station 22 into the stacker 23.

The feed bed as indicated in FIG. l contains a plurality of accelerating and retarding jets or ducts 26 which are uniformly spaced along the length of the feed bed and are connected through, for example, flexible hoses 27 to the uid sequencer 25. In operation the sequencer 25 functions to simultaneously energize at one instant of time a group of accelerating jets 26 associated with the 3 rear portion of the document and another group of retarding jets 26 located near the front portion of the document. In the next instant of time, the sequencer switches and the group of accelerating and retarding jets which are then energized are displaced one jet position to the right of that previously energized. The switching rate is controlled by the sequencer 25 and the effect in the card bed is similar to having two displaced pressure wave fronts which are propagated down the bed carrying the document between the two wave fronts.

As shown in FIGURES 2 through 5 to which reference is now made, applicants novel feed bed comprises a top plate 28, a bottom plate 29, an end plate 32 and two side plates 30 and 31 which are all assembled, bolted for example, or glued together so as to form a box-like structure.

The construction can be made of plastic, or metal, or other air impervious materials. Dividing the space between the top and bottom plates 28 and 29 is a septum 33 which is located intermediate the top and bottom plates to provide a plenum chamber 34 for reasons which will be subsequently described.

Supported on top of the septum and secured thereto such as by gluing are a plurality of longitudinal rib members 36 which run the length of the feed bed and which terminate short of the top plate so as to provide a channel area 37 between the underside of the top plate and the top of the longitudinal rib members 36. The channel 37 which has an entrance or throat 37a has a depth which is slightly larger than the thickness of the document and a width slightly wider than the document so that channel 37 defines the conveyor track for the document. Each of the longitudinal ribs 36 has a series of bore holes 38 formed therein with bore holes 38 in the two endmost ribs being aligned with a series of bores 39 formed in the side plates 30 and 31 whereby the interior of the card bed is vented to the atmosphere to thereby provide a pressure relief for the accelerating and retarding jets.

Disposed in the top plate 28 are typically four longitudinal rows of air jets, A, B, C and D although a fewer or greater number of rows may be used if desired. Each of the rows contain a plurality of uniformly spaced and transversely aligned jets which may be distributed for example at three-quarter inch intervals along the length of the feed bed. The outer two rows A and D form the accelerating jets utilized in the invention, whereas the inner two rows B and C comprise the retarding jets. Each of the jets comprises a channel portion 40 which terminates in a nozzle portion 41 at the underside of the top plate 28. The nozzle portion 41 of the accelerating jets (FIGS. 2 and 4) may subtend for example an angle of thirty degrees relative to the horizontal and is arranged so that when pressure is applied to the jet tting exemplified at 42 through a flexible hose coupling for example, an air jet will be formed by the nozzle portion 41 having a horizontal component of force going from left to right in FIGURE 2.

The retarding jets which comprise the inner two rows B and C of jets are similar in construction to the accelerating jets except that their nozzle portion 41 has an opposite angular orientation as shown in FIGURE 5. Here again the retarding jets include a channel portion 40 which may be rectangular or round in shape which is terminated at the underside of the top plate 28 in a nozzle portion 41 angled again aproximately thirty degrees to the horizontal but in opposition to the angled orientation of the accelerating jets of rows A and D.

As will be apparent from the previous description, the document is supported in channel 37 on top of the rib members 36 and is moved under the influence of the accelerating and retarding jets. To facilitate movement of the document down the channel 37 an air bearing system may be provided which has the effect of lifting the document off of the longitudinal ribs 36. For this purpose the ribs 36 contain a series of uniformly spaced bore holes 43 which communicate through matching holes 44 in the septum 33 with the plenum chamber 34. A suitable hose fitting for example 45, connects an aperture 46 formed in the bottom plate 29 to a source of air pressure whereby air may be admitted into chamber 34 under pressure. The pressurized air in plenum chamber 34 leaks through the openings 44 and bore holes 43 to provide an air bearing on the other side of the document as it passes along the channel 37.

While numerous modes of energization of the accelerating and retarding jets are possible one typical and perhaps preferred mode is shown in FIGURE 6. As herein illustrated thirteen transverse columns of accelerating and retarding jets are shown over which has been superimposed in outline form a document indicated in general at 47. The document has for purposes of illustration a length corresponding to approximately eight columns of jets and is positioned with its trailing edge intermediate columns 3 and 4 and its leading edge intermediate columns 11 and 12. Two columns of accelerating jets A and D, here shown as columns 3 and 4 are simultaneously energized with two columns of retarding jets B and C, here shown as columns 11 and 12. ln this condition the document 47 is stabilized in the position indicated since the units of accelerating force applied to the document are in balance with the units of retarding force applied to the document. In this example four units of force are applied by both sets of jets. To move the card or document 47 in a left/right direction as shown in FIGURE 6, the two columns of energized accelerating jets are shifted one position to the right to columns 4 and 5 simultaneously with a similar right shift of the two columns of retarding jets to columns 12 and 13. The card will then move to the right one jet position since after the jets have been switched and before the card moves it will be apparent that the applied forces are out of balance. Specifically, there will be four units of accelerating force applied to the document by the accelerating jets in columns 4 and 5 while there will be no units of force applied by the retarding jets in column 12. There will then exist a net force of four units to the right tending to move the card to a new point of equilibrium where the units of force provided by both the retarding and accelerating jets are equal.

It will be apparent therefore that the card will move in the direction in which the jets are switched and at a rate corresponding to the sequence rate of the switching of the jets. It should also be apparent that the position of the document is always such that the accelerating and retarding forces applied thereto tend to be in balance. Hence any fortuitous movement of the document from its position of balance will cause forces to be applied thereto which tend to restore the document to its balanced position.

A second mode of jet energization exists where all the accelerating jets in rows A and D are continuously energized and a group of retarding jets corresponding, for example, to approximately half the length of the document are energized. In this mode of operation and with the document 47 in the position shown in FIGURE 6 the retarding jets in columns 8 through 12 are energized as a group during one instant of time and in the next instant of time the retarding jets occupying column positions 9 through 13 are energized as a group. This mode requires that the magnitude of the individual retarding jet be greater than that of the individual accelerating jet since in this mode, the l() retarding jets in columns 8 through 12 must balance the 18 accelerating jets in columns 3 through 11.

A third mode of jet energization is that of energizing a group of accelerating jets corresponding to the half length of the document simultaneously with another group of retarding jets also corresponding in number to the half length of the document. In this mode the accelerating jets occupied by columns 3 through 7 in FIGURE 6 would be energized simultaneously with the excitation of the retarding jets in columns 8 through 12. The sequencing is then done by switching the energized accelerating jets from columns 3 through 7 to 4 through 8 simultaneously with switching the energization of the retarding jets from columns 8 to 12 to columns 9 to 13.

From the foregoing it will be apparent that the underlying theory of the present invention is that the document always tends to move so as to maintain the forces applied thereto in balance. It will be appreciated therefore that the foregoing modes are exemplary only and are not exhaustive.

While the pressure requirements for propelling the documents are not critical it is apparent that for higher speeds of operation higher jet pressures are required since the jet is on for a shorter period of time as the sequencing speed goes up.

One suitable form of sequencer 25 is a fluidic shift register such as shown in FIGURE 7, to which reference is now made. It will be understood that the shift register as shown in FIGURE 7 would be used to operate, for example, the accelerating jets for the mode shown in FIGURE 6 and that another similar type shift register is required to operate the retarding jets. As indicated in this figure, the shift register contains a plurality of bistable type fiuidic elements equal in number to the number of columns of accelerating jets disposed along the feed bed. Each stage of the shift register comprises a well known type of bistable pure fluid amplifier such as is represented at 50 in stage one. This amplifier comprises a power input channel 51 and left and right output channels 52 and 53. This amplifier which is of the boundary layer type operates so that fluid flowing up the power input channel 51 will either discharge through the left output channel 52 or the right output channel 53 and once fluid is established in either one of these output channels it will continue to flow out that output channel until a control pulse is applied to the appropriate one of the two control channels 54 or 55. In the illustrated connection the left output channel 52 discharges into the atmosphere or into a suitable recovery chamber from which other fluidi-c elements in an overall document processing system may be powered whereas the right channel 53 which may -be termed the active output is used to excite the accelerating jets of the card bed. To this end, fluid flowing out of the right channel 53 is split by divider 54a, half flows out through a duct 55a to the accelerating jets shown at column 1 in FIGURE 6, while the remainder fiows out through fluidic OR device 56 and duct 57 to the accelerating jets of column 2 shown in FIGURE 6.

At the start of the card transporting operation a fluid reset pulse is applied to a duct S8 which connects through the corresponding OR gate 59 to the right-hand control nozzle 55 of each of the bistable amplifiers in the shift register. The reset pulse then has the action of resetting all the fluid amplifiers 50 in the shift register so that the power iiuid flows out the inactive channels 52 in each of the stages. To start the card moving down the bed, a start pulse is applied to the left control nozzle 54 of the first stage in the chain. The start pulse switches the power iiuid to output channel 53 which in turn energizes the accelerating jets in columns 1 and 2 of the feed card bed. At some point in time after the start pulse, a periodic fluid clock pulse is applied to duct 60 and thence through a corresponding control channel 61 to each of the stepping AND gates 62 of the shift register. Immediately following the start pulse only the first stage of the shift register has been lswitched to its right hand output 53 and through connection 53a only the first AND gate 62 will be enabled. Thus the first clock pulses following the start pulse will produce an output from the first stage AND gate 62 which is applied through channel 63 to the lefthand control port 54 of the second stage of the register and nearly simultaneously therewith through OR gate 59 to the right-hand control port S5 of the first stage of the shift register. The gate 62 output pulse applied to the control port 5S resets the first amplifier so that the power fluid now flows out the inactive channel 52 while the pulse applied to the right-hand control port 54 of the second stage sets the second stage of the shift register so that the fluid power flowing therethrough now flows out the righthand or active channel 53 thereby energizing the accelerating jets in column positions 2 and 3` through OR gates 56 and 56. Thereafter, the next clock pulse passes through AND gate 62, stage 2, to reset stage 2 and set stage 3 thereby to energize the accelerating jets in column positions 3 and 4. Thus it will be seen that each fiuid clock pulse applied to duct 60 acts to reset the iiuid amplifier which is presently set and at the same time set the next successive amplifier in the chain whereby the energization of the jets will progress down the feed bed at a rate corresponding to the clock rate of the pulses applied to the clock channel 60.

As previously indicated a similar type shift register operating synchronously with FIGURE 7 would be used in energizing the retarding jets to achieve the sequencing mode of FIGURE 6. A similar arrangement of shift registers would be used to achieve the above-described third mode of excitation except in this case t-he active output of each stage would be used to energize groups of five accelerating and retarding jet columns. For the second mode of energization above-described, however, only a single shift register need be employed. In this embodiment the single shift register would be used to control and sequence the energization of the retarding jets.

The foregoing types of energization may be referred to as digital since they operate to provide short pulses of power to each of the jets in sequence. An alternate type of energization, which may be referred to as analog, is shown in FIGURES 8 and Sa to which reference is now made. In this system of energization, the jets both accelerating and retarding along the card bed are excited by a time lvarying waveform such as a sine wave. In more particular, the fluid energy applied to each of the jets is phase shifted by a uniform amount approximately equal to l/nX where n equals the number of jet columns spanned by the document. As an example, assume that the document spans 7 jet columns then the phase shift between each successive accelerating jet approximately equals 26 when the phase difference -between pressure peaks is assumed to equal 360. At the same time the retarding jets are similarly energized except from a phase opposed iiuid source. Using this schedule of jet energization, it will be seen that the forces applied to the document by the accelerating jets peak at the trailing edge of the card and fall off uniformly to near zero at the leading edge of the document. At the same time the forces applied to the document by the retarding jets peak at the leading edge of the document and fall to near zero at the trailing edge of the document.

Referring now to FIGURE 8 the structure for effecting this type of energization includes a fluid wave generator 70 which provides in one output channel 71, a time varying signal pressure wave, for example a sine wave, and in output channel 72, another time varying signal which is in phase opposition to that appearing in output channel 71. These outputs are applied to the input of a multistage delay or phase shift chain which then excite or energize the accelerating and retarding jets in the manner indicated in the figure. For purposes of simplicity, only three stages of the delay chain are shown. Each stage of the delay chain includes a well known pure fluid proportional arnplifier indicated at stage one by the reference character 73. Each amplifier includes a power input channel indicated at stage 73 by the reference character 73a, a pair of control channels which are indicated at 71a and 72a, and a pair of output channels 74 and 75. The normal action of the proportional amplier is such that power fiowing up the input duct 73a divides and will flow out output channels 74 and 75 in accordance with the amplitude of the input signals applied to the input control ducts 7 71a and 72a. Specifically, when the input to 71a is a maximum the input to 72a is a minimum and maximum output appears at output channel 75 and essentially zero output appears at output channel 74, and when the inputs to controls 71a and 72a are equal the outputs at 74 and 75 are equal. Thus the outputs at 74 and 75 follow the time variation in the inputs. The outputs of the first stage 73 are applied through phase-shifting delay elements 76 and 77 to the control inputs of the second stage 90 of the chain and the outputs of the second stage are applied through phase-shifting delays 78 and 79 to the control inputs of the third stage and so on. In addition the output 74 of stage one is applied in the accelerating jets in column position #1 while the output channel 75 is applied to the retarding jets in column position #1. Since the amplifiers in the delay chain are inverting in nature, the output 90a from the second stage 90 is applied to t-he accelerating jet while the output 90b is applied to the retarding jet in column position #2 and so on. This interconnection proceeds along the length of the card bed in an obvious manner.

With the interconnection shown when the accelerating jet an column #l is at a maximum the retarding jet in column position #8 will also be at a maximum, assuming a 180/11 degree phase Shift per stage where 27. At this same time point in time, the pressure distribution provided by the acceleratingy jets uniformly decreases to zero at jet position #8 while the magnitude of pressures applied by the retarding jets in column positions 1 to 8 uniformly increases from a minimum at column 1 to a maximum at column position #8. With this scheme the card or document will tend to position itself between the two highest pressure points with the leading edge of the card being in registration with the highest pressure retarding jet and the trailing edge of the card in registration with the highest pressure accelerating jet and move with these pressure points as they propagate down the bed.

The fiuid wave generator 70 shown at FIGURE 8 can assume various forms. One typical form is shown in FIG- URE 8a to which reference is now made. As herein illustrated, the generator would typically include a bistable type fluid fiip-fiop indicated at 80 which includes a bistable pure fiuid amplifier having a pair of feed back paths which contain suitable delay elements 81 and 82 arranged so that a natural oscillator is formed. The frequency of oscillation of the oscillator has a value which is suitable for operation of the system involved. The oscillator 80 provides a square wave output which has one phase appearing in output duct 83 and an opposite phase appearing in output duct 84. These two outputs are then coupled through suitable wave shaping elements such as the capacitor elements 85 and 86 to the inputs 85a and 86a of a proportional type amplifier 87 which will provide the shaped wave outputs in channels 71 and 72.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a document feeder, the combination comprising; a document feedbed, a first set of air nozzles positioned along the length of said feedbed and angled in one direction relative to said feedbed, a second set of nozzles positioned along the length of said feedbed and angled in a second direction opposite to said first direction, and means for simultaneously energizing said first and second sets of nozzles so as to provide through said first and second sets of nozzles first and second equal and opposite forces acting simultaneously on a document to be transported along said feedbed, said means further including a control means for shifting the energization of said sets of nozzles so as to cause a positional shift of said forces along said feedbed and to thereby propel the document to be transported in either of two directions along the feedbed.

2. The structure of claim 1 wherein the nozzles comprising the first and second sets are arranged in parallel rows alongT the feedbed.

3. The structure of claim 1 wherein said control means comprises means for modulating the air pressure supplied to said first and second sets of nozzles.

4. The structure of claim 1 wherein said control means comprises means for sequentially energizing said first and second sets of nozzles.

5. The structure of claim 1 wherein said control means comprises means for continuously energizing said one set of nozzles and for sequentially energizing the other set of nozzles.

6. The structure of claim 1 wherein said control means comprises means for sequentially energizing groups of said first and second sets of nozzles.

7. The structure of claim 1 wherein said control means comprises means for continuously energizing said one set of nozzles and for sequentially energizing groups of said second set of nozzles.

8. The structure of claim 1 wherein said first and second sets of nozzles are located on one side of said feedbed and a series of air bearing nozzles are disposed along the other side of the feedbed.

9. The structure of claim 1 wherein the nozzles of the first and second sets energized by said means are spaced from one another by a distance approximately equal to the length of the document to be transported.

10. The structure of claim 1 wherein said control means operates to vary the air pressure applied to the first set of nozzles in a first sense along the length of said feedbed and to simultaneously vary the air pressure applied to the second set of nozzles in the opposite sense along the length of said feedbed.

11. A document feedbed comprising, a support member extending the length of said feedbed, a plurality of transversely spaced rib members supported on said support member and extending along the length of said support member, a top plate overlying the said rib members and spaced therefrom to form a document channel along which a document may be propelled, a series of fiuid nozzles spaced along the length of said top plate, a first set of said nozzles being oriented so that when energized by fiuid under pressure they will produce a component of force extending in one direction along the document channel, a second set of said nozzles being oriented so that when energized by fluid under pressure they will produce a component of force extending in an opposite direction along the document channel and means for simultaneously energizing said first and second sets of nozzles so as to provide through said nozzles first and second equal but opposite forces acting simultaneously on a document to be transported along the document channel, said means further including a control means for shifting the energization of said sets of nozzles so as to cause a positional shift in said forces acting on the document thereby to propel the document along the document channel.

References Cited UNITED STATES PATENTS 1,854,560 4/1932 Owens 198-204 3,103,850 9/1963 Khoury 271-74 RICHARD E. AEGERTER, Primary Examiner.

U.S. Cl. X.R. 271-74; 302--29 

